Method of producing hydrocarbon from hydrocarbon-bearing earth-strata.



.f I. L. DUNN.

METHOD 0F PRODUCING HYDROCARBON FROM H YDROCARBON BEARING EARTH STRATA.

APPLICATION FILED SEPT.2I, 191.1. 1,1 90,267. Patented Ju1y11, 1911;.

- ir/i@ 'fr Irwin/Z .17u/1li UNITED STATES ra'rEN'rA oFFrcE.

- IRWIN L. DUNN, LONG BEACH, CALIFORNIA, ASSIG-NOR TO PETROLEUM PATENTS COMPANY, OF CHICAGO, ILLINOIS, CORPORATION OF- MAINE.

METHOD 'OF IPRODUCING HYDROCARBON FROM HYDBOCARBON-BEARINGEARTH STRATA; i

Patented July 11, 1916.

Application led September 21, 1911. SeriaLNo. 650,640?.

To all whom may concern.'

Be it known that I, IRWIN L. DUNN, a

'citizen of the United States, residing lat- Long Beach', in the county of Los Angeles and State of California, have invented a new and useful Method of Producing Hydrocarbon from Hydrocarbon-Bearing Earth-Strata, of which vthe following is a specification.

This application is intended to cover subject-matter divided out Vof .my-appllcation Serial No. 620854, filed April "13,' 1911, on which, Patent No. 1,067,868 was granted July 22, 1913, formethod of increasing the productiveness of oil and gas wells.

This invention also includes certain further improvements as will hereinafter more clearly appear. f'

' It is well known; that hydrocarbon-bearing earth strata may's'imultaneously contain water, 'hydrocarbon liquid fand hydrocarbon gas; that by the force of gravity the water seeks the lowest level, the liquid a higher level and the gas the highest level; that a Well entering said strata may supply gas, oil

or water depending upon where it taps the strata, and Aalso that such well may simultaneously supply oil, gas and water, or oil and gas, or oil and water, or gas alone as the conditions determine.' It is lalso well known that the production. of'hydrocarbon from such strata diminishes as the gas pressure decreases.

It is a well-known fact thatin order that any oil sand may be productive, it must be covered with a tight roof and tight bottom;l

otherwise, gas, together with other hydrocarbon, escapes, and we find the reservoir sand exhausted. In drilling .into a virgin territory we find the rock pressure approximately equal'to one-half the average depth of the producing strata. From time to time, if the rock pressure be tested' as the wells decrease in production, such pressure vis found to be continuously reducing. In other words, an oil territory continues to'produce until the gas held in the interstices of the rock has expanded to atmospheric pressure. y

lAfter this, gas pumps are employed to create a vacuum, and thus increase the flow of rock by capillary attraction. I have found by renewing -this pressure by artificial means-either through the producing wells,

. or abandoned wells in the same strata-that great quantities of oil can be produced from the old and unproductive oil fields: in fact, my experiments lead me to believe that not over twenty-five per cent. of theoil has been taken out of the rock, and thatmost of what remains may be recovered and used.

An object of this invention is -to recover from the hydrocarbon-bearin as large a percentage as possi le of the hydrocarboncontained.therein and to produce l.such product in a manner entirely at the control of the producer and in suchform, also at the control of the producer, asma-y be most desirable for transportation and use.

I apprehend thatfor manufacturing and,

domestic purposesand for ready and convenient vtransportation within certain limits fromthe'producing well to the burner Where earth strataused the best form in which hydrocarbon Y may be produced from earth strata, is the gaseous form; and by the method herein described and Vclaimed it is made possible at low cost and inexpensive mechanism, to supply from hydrocarbon-bearing strata, combustible gas as required, and under any desired pressure within practical limits.

In the parent application Serial No. l 620,854, I have claimed the newly-discovered art generically and have specifically claimed the process -of reproducing hydrocarbons from earth strata by introducing into such strata natural gas under pressure from other earth strata, thus more or less fully restoring the .rock -pressureyand allowing said rock pressureh to displace the hydrocarbons from. the pores and interstices of the strata to a place where they may be recovered.

The subject-matter of-the present invention is broadly noveland of a pioneer nature in that it l.treats 'the hydrocarbon bearing earth strata and the roof and floor thereof as constituting an immense fully charged carbureter into which atmospheric air may be pumped for the purpose of removing the hydrocarbons. The atmospheric l air thus serves two purposes, one being lto displace pumped into'the hydrocarbon bearing vstrata i oil. After all known methods have been.

liquid form available at a Well that reaches the proper level in the earth strata; and

second, to displace the hydrocarbon byl absorption into theairfso that the air recovered from the strata will be highly carbuother refined products. The heavier hydrocarbonsmust be pumped unless sufficient -alr pressure is applied to produce a flowing well. It is thus seen that by introducing atmospheric air under pressure to hydrocarbonbearing strata, the highlyvolatile hy` drocarbons may be recovered as combustible gas suited to immediate use for power, light and heat; that refined liquid hydrocarbon may be produced from such gas; and that l heavier liquid hydrocarbon may be recovered either by pumping the liquid from a well or byy applying the air pressure so forcibly onl top ofthe liquid as to produce a flowing well. Said air pressure may be introduced into the strata at the top thereof or at any other point or points and will eventually produce a gaseous pressure down on top of any liquid bodyvthat may be or may accumulate in the stratumv or strata closed in by the impervious floor and roof, care being' taken, ofcourse against undue emission orescape of the contents of the strata by closing all outlets except' those from which the hydrocarbons are to be taken.

By this invention substantially all of the `hydrocarbons within the-area 'designed to be worked by the apparatus can be drawn from t-he earth, and to effect this there is first created an artificial pressure upon the liquid hydrocarbons within a given zone, and said zone is tapped at different levels so as to draw off both liquidand gaseous hydrocarbons. I employ compressed air to produce the artificial pressure and such compressed air acting upon the more volatile constituents of the liquid hydrocarbons produces an inflammable gas which is drawn ofi1 from the stratum that lies immediately above the liquid hydrocarbons so that said gas is not lost. It is clear that liquid hydrocarbons' are not only expelled or lifted, or at least partially raised, from the hydrocarbon-bearing stratum by the pressure of the compressed air but that said compressed air gasifies a large percentage of the liquid hydrocarbon which is subsequentlydrawn off above said stratum, thus minimizing the expense of obtaining the hydrocarbons.

The herein claimed method will be understood by reference to the accompanying drawings.

Figure l represents in a conventional way production is 'noted at the wells.

Lianne? a portion of a hydrocarbon bearing field in vertical section with apparatus for carrying out the invention and for recovering the hydrocarbon from the earth strata in sev. eral ways. Fig. 2 is a conventional representation in fragmental vertical section of a hydrocarbombearing field and apparatus by which the method may be employed to recover liquid hydrocarbon by pumping the same from the same Well into which the air pressure is pumped#` i 'lhe lower part of thev Well is hermctically sealed from the'interior of the well casingl by packing 2, so that the gaseous medium introduced -into the hydrocarbon bearing strata 3 will not escape above the impervious formation .4'. The pipe 5 packed by the packing 2 in the casing is connected with the air compressor a, and delivers the compressed air to the strata 3.

The pump 6 is located below the surface of the accumulated oil 7 at the bottom off the-well a and is sealed from the compressed air by the oil body. So long as the output of the well is not sufficient to unbalance the seal 7,' the rock pressure will remain in the strata to assist in producing oil at the pump;. and so long as theseconditions prevail, oil alone will be pumped and gas may be taken ofi' from other parts of the field either through flowing wells Z o1" through gas wells e, f, as shown in Fig. 1.

Any suitable well-known air compressor, as a bellows, an air pump, three phase com'- pressor, or the like, may be employed for forcing compressed bon bearing strata.

In Fig. 1 the air compressor av is connected witha well a which is hermetically sealed in any well-known way as detailed in Fig. 2, and is arranged to conduct the air into the hydrocarbon bearing formation 3. Otherv Wells, c, d, e, f, enter the same strata at other stations. The air from the air compressor permeates the earth strata to a greater or lessextent producing what is called rock pressure. I have `found in actual practice that where the wells have been pumped in a vacuum the air flows in to the exhausted hydrocarbon strata with great readiness, thus showing that a vaccum air into the hydrocaris being filled, and that when the rock pressure reaches an appreciable amount, say three or four pounds, valuable increase 1n The amount of production in the field may be regulated by regulating the rock pressure which is thus produced. The `air flowing intothevstrata 3 from the Well a will displace the liquid hydrocarbon from the interstices and pores of the rock or other formation where it is held by capillary attraction. or other forces, and will be caused Ato flow to a lower level; the natural tendency l ofthe air being to seek the highest level.

In wells Z) and c it may be assumed that the'oil does not rise yto the surface ofthe ground, and mustbe pumped, while in well l d the surface'of the ground is at a lower level andthe rock pressure may be suiicientto lcause the well to flow. Furthermore the bottom of the well d is shown at a higher level, so that gas and oil may both be discharged from such well, thus tending to produce a flowing well, while practically no air escapes from the wells b and c.

Wells e and f tap the strata 3 at a level It is understood thatv in some instances suflicient air may be introducedl at one well for an entire field or fora large portion of a field, orfor a large number of wells; and that the recovery of the hydrocarbons from all of the wellsmay proceed simultaneously with the air pumpingv operation, the air inv effect filling the upper portion of the hydrocarbon-bearing strata and the liquid hydro-l i carbon being -removed from the wells respectively by pumps having their inlets entirely below the surface of the accumulated liquid hydrocarbon bodies. In any event all of the wells in the formation where the rock pressure is restored will produce hydrocarbons and the same may be drawn off by pumps or otherwise as required.

Whenthe hydrocarbons have been produced at the top' of thewell they may be. handledin any appropriate'manner as for instance, the heavy hydrocarbons may be rened and the lighter hydrocarbons coming oli' as gas may be condensed or syntheti-u cally reduced to the required product. Such of the lighter hydrocarbons as are liquid at about the ordinary temperatures and pressures may be readily condensed from the air in ordinary condensers by cooling -with or without the application of pressure. nd the hydrocarbon-s which are gaseous atl normal .temperatures may lilre-v wise be condensedv by known methods of ex tracting the heat therefrom and applying ,pressure thereto, the cooling and compression, however,bei ng necessarily of higher degree, as. will be readily understood by those skilled in the'art.

I claim hydrocarbons from the earth which coni' foo A method'of obtaining the lighter liquid' sists in forcing'atmosphericy air into hydrocarbon bearing strata thereby carbureting the same, drawing off thecarbureted-airso produced, and condensing the hydrocarbonsfrom said air to aliquid form.

' In testimony whereof, I have hereunto set my hand at Marietta Ohio this 19th day of September, 1911."

. ,l IRWIN. L.r DUNN.

In p'resence'of-- y A .l

. T. J.- SUMMERS,

A RUTH E. RITTER. 

